This invention relates generally to infra-red (xe2x80x9cIRxe2x80x9d) remote control devices and, more particularly, to learning types of remote control devices.
Infrared remote control transmitters for controlling various functions of television receivers, VCR""s, cable decoders and auxiliary equipment have become quite widespread in recent years. The result is often that a user is confronted with a number of different remote controls for controlling various devices made by different manufacturers. Most manufacturers provide transmitters to control their various devices, i.e., TV, VCR, stereo, by re-configuring the transmitter keyboard with a key or switch or the like, and devices of different manufacturers are controlled with different xe2x80x9cdedicatedxe2x80x9d remote control devices. To minimize the number of individual remote control devices a user requires, xe2x80x9clearningxe2x80x9d universal remote control transmitters have been developed. In a common method of setting up and using universal remote controls, the IR function codes that are to be learned are made available from a teaching transmitter. Learning is accomplished by positioning the teaching and learning transmitters such that IR signals from the teaching transmitter are received by the learning transmitter (remote control device). Next, a program is followed which includes sequentially transmitting the IR function codes associated with the keys of the teaching transmitter to the learning transmitter. The learning transmitter stores the detected IR function codes in its memory and essentially re-configures its keyboard so that the appropriate IR function codes may be transmitted to the device to be controlled. Television sets, VCR""s, entertainment media, and other devices can thus employ universal or standard remote controls that can be adapted to control various and sundry brands. Thus, universal remote control devices can learn the commands for controlling each of the various brands and types of devices.
U.S. Pat. No. 5,691,710 issued to Pietraszak et al. and assigned to Zenith Electronics Corp. discloses a self learning IR remote control transmitter of the type mentioned above. U.S. Pat. No. 5,255,313 issued to Darbee and assigned to Universal Electronics Inc., and U.S. Pat. No. 5,552,917 issued to Darbee et al. and assigned to Universal Electronics Inc. also disclose universal remote control systems. The present invention provides an improvement to the circuitry of the systems disclosed in the above-mentioned patents.
It is known that, in addition to the ability of light emitting diodes (xe2x80x9cLED""sxe2x80x9d) to provide IR signals, LEDs may also have the ability to receive, be sensitive to, and react to incoming light. One such receiver type of IR circuit is disclosed in U.S. Pat. No. 4,933,563, issued to Thus and assigned to U.S. Philips Corp. Some of the embodiments disclosed in the present invention exploit this dual effect or capability of IR diodes to transmit and receiver IR signals; this feature minimizes the circuitry used with learning remote controls, and also facilitates the retrofitting of learning capability to existing remote control designs, since no re-tooling of the plastic case is needed to accommodate a separate IR receiver.
This invention provides improved IR diode circuits for use with learning remote controls. In some of the disclosed embodiments, the same IR LED is utilized to transmit and to receive IR signals; and, the inventive circuitry is a component of the IR output circuit for a remote control. In another of the disclosed embodiments, improved circuitry is provided for a transmitter IR LED and a separate receiver IR photo detector diode, and a method if disclosed whereby the IR photo detector can be mounted behind, and receives light input through the plastic encapsulation of, the transmitter IR LED.
The foregoing features and advantages of the present invention will be apparent from the following more particular description of the invention. The accompanying drawings, listed hereinbelow, are useful in explaining the invention.